辽河西部凹陷稠油油藏特征及其成因探讨

辽河油田西部凹陷稠油资源丰富,分布广泛,类型多样,地化特征显著。根据原油的成熟度、生物降解程度及生物降解后油气的注入情况等多元因素,将该区稠油划分为原生稠油、降解型稠油及降解—混合型稠油。西部凹陷稠油成因主要为生物降解作用,水洗作用和氧化作用则促进了原油稠化,而温度、地下水、化学条件及构造条件等是控制原油降解程度的主要因素。

Characteristics and Genesis of Heavy Oil Reservoir in Western Depression,Liaohe Basin

There are abundant,distribution of a wide range,various types and obvious geochemical characteristics of heavy oil reservoir in Western depression of Liaohe basin.According to maturity of crude oil,degree of biodegradation,and oil input after biodegradation,the heavy oils in Western depression are divided into three main types which are connate heavy oil,degradation heavy oil and degradation-mixed heavy oil.It is found that most of the secondary heavy oils are subjected to biodegradation,water washing and oxidation,which degrade,delete,or oxidize the hydrocarbons in oil.The result shows that degree of oil degradation in the area are mainly determined by such factors as temperature,groundwater,chemical conditions and tectonic conditions,etc.